html,body {
    width: 100%;
    height: 100%;
    margin: 0;
    padding: 0;
    overflow: hidden;
}
.container {
    display: flex;
    position: relative;
    width: 100%;
    height: 100%;
    flex-direction: row;
    align-items: center;
    justify-content: center;
    background-color: #0f222b;
}
.box {
    position: relative;
    width: 200px;
    height: 200px;
    color: #3083ff;
    background: url('./img/Button-White-Large.png') no-repeat 50%/70% rgba(0, 0, 0, 0.1);
    box-shadow: inset 0 0 0 1px rgba(106, 150, 207, 0.5);
}
.box::before, .box::after {
    position: absolute;
    top: 0;
    bottom: 0;
    left: 0;
    right: 0;
}
.box::before, .box::after {
    content: '';
    z-index: -1px;
    margin: -5%;
    box-shadow: inset 0 0 0 2px;
    animation: clipMe 8s linear infinite;
}
.box::before {
    animation-delay: -4s;
}
@keyframes clipMe {
    0%, 100% {
        clip: rect(0px, 220px, 2px, 0px);
    }
    25% {
        clip: rect(0px, 2px, 220px, 0px);
    }
    50% {
        clip: rect(218px, 220px, 220px, 0px);
    }
    75% {
        clip: rect(0px, 220px, 220px, 218px);
    }
}